Done the trip from Newcastle to Rocky and beyond a few times , always took the coast road (on orders from Mrs and Jr) , until the last trip , and that's OK the first time , but hundreds of km of bananas and then sugar cane .... :ZZZ: and the heavy vehicle and tourist traffic makes it very stressful and risky .... some of those long haul truck drivers are crazy .... not much fun being tailgated by a monster truck for 60 - 100 km , some of the Pacific Hw is very narrow .... and there's no where to go.
Unless I need to do the coast run or plan on frequent fishing sessions along the way , I will in future do the inland run .... it's better.
My advise is take the New England HW -> Gwyder HW --> Leichart HW and stay on the western side of the mountains , also most direct route. ... the route can be planned here , 1300 km , vs 1500-1600 via Bris and the coast routes
http://www.whereis.com/index.htm#session=MTEy
You'll not have hundreds of km of banana and then sugar cane on either side of the high way, you'll not have as much traffic to worry about, accomodation at country towns along the way will not be booked out like on the Pacific Highway.
It's a much nicer drive (I like the outback)
You can avoid Brisbane and Surfers altogether !!!
DARKER CLEARER SKIES !!!!